38 
made with water containing 1 *4 grains of ammonium nitrate 
and 42 grains of calcium chloride per gallon; the amount ol 
lead dissolved, after 72 hours being only 0126 grains per 
gallon, whereas water containing the same amount of 
ammonium nitrate, but without the addition of any other 
salt, dissolved D75 grains per gallon, or about fifteen times 
as much lead in the same time. As a water which contains 
nitrates very often also contains chlorides this reaction is one 
of some importance. 
Under certain circumstances there can be no doubt that 
water will dissolve considerable quantities of lead, this is 
especially the case with water charged with carbon dioxide, 
and with hot water 
Dr. Roscoe has described a case in which a leaden cistern 
was very quickly acted upon by hot water.* 
For the following details regarding the amounts of lead 
found in various samples of aerated beverages in the manu- 
facture of which leaden apparatus had been employed, I am 
indebted to my friend, Dr. Milne, of Glasgow. 
Table B. 
Lead found in various samples of aerated beverages . 
Description of Quantity of Lead in 
Liquid. grains per gallon. 
Lemonade 0*20 
Do 0*40 
Do 0-05 
Gingerade 0T0 
Sodawater — O’GO 
Do 0-05 
In addition to these numbers I have determined the follow- 
ing, which show the amounts of lead dissolved by distilled 
water charged with carbon dioxide at the ordinary 
atmospheric pressure for varying lengths of time, and also 
the amounts dissolved by the same water on the addition of 
various salts. The surface of lead exposed measured 2,100 
square millimetres. 
# Proc. Lit. and Phil. Soc., of Manchester, Vol. xiv., p. 23. 
